Comment # 6 on bug 1200977 from Dr. Werner Fink

(In reply to Franck Bui from comment #5)
> You need to provide the logs when the problem actually occurs otherwise
> they're not useful.
> 
> Also I think that simply enabling the systemd debug logs just before
> rebooting should be enough since the problem seems to appear when umounting
> /run/user/* which should happen pretty early during the shutdown process.
> 
> Hence please try to reproduce by simply doing `systemctl log-level debug;
> reboot` (preferably on TW).

At this point the sssd should run as well as the network should be up or
otherwise the ldap access does lock this umount even if local.